(NR) Sept 30: Density and Graphing

Density

- The density of an object is its mass divided by its volume. It is usually expressed in kg/L, kg/m^3, or g/cm^3.

example:

1) Determine the density of the hot tub that has the mass of 115kg and a volume of 70L.

d = 115 kg 
        70L

  = ____kg/L




(answer: 1.6 kg/L)

Graphing

• All graphs MUST contain 5 important things:
  1) Labelled axis
  2) Appropriate scale
  3) Title
  4) Data points
  5) Line of best fit line
• Three things can be done when working with graphs:
  1) Read the graph.
  2) Find the slope (RISE/RUN)
  3) Find the area under the graph.
  
  
  
  

m1) rise = 4                           m2) rise = 2                          m3) rise = 4                              m4) rise = 2      
       run     1                                  run    1                                 run     2                                     run     1
             
      = 4 miles/hour                 = 2 miles/hour                       = 2 miles/hour                           = 2 miles/hour

m5) rise  = 0
       run     1
    
     = 0 mile/hour

AREA:

a = 1/2bh = 1/2(1)(4)                                   d= 1/2bh = 1/2(1)(2)
               = 2                                                               = 1
                                                                     = lw       = (10)(1)
b= 1/2bh = 1/2(1)(2)                                                  = 10
              = 1                                                 = 11
  = lw     = (4)(1)
             = 4                                                 e= lw     = (12)(1)
 =  5                                                                         = 12

c= 1/2bh = 1/2(2)(4)                                 
              = 4                                               TOTAL AREA: a + b + c + d + e
  = lw     = (2)(6)                                                                 = 2 + 5 + 16 + 11 + 12
             = 12                                                                      = 46 miles x hour
= 16